public function calcul_mois()
 {
     $tab = Feries::chargement();
     if (date('n') <= 6) {
         $annee = date('Y', strtotime('-1 year', strtotime(date('Y'))));
     } else {
         $annee = date('Y');
     }
     $rentree = Feries::jour_rentree($annee, $tab);
     $rentree = date('Y-m-d', strtotime('-' . (date('N', strtotime($rentree)) - 1) . 'day', strtotime($rentree)));
     $mois = [];
     while ($rentree < date('Y-m-d', strtotime('+2 months', strtotime(date('Y-m-d'))))) {
         $fin = Feries::deux_mois($rentree);
         $mois[] = ["debut" => $rentree, "fin" => $fin];
         $rentree = $fin;
     }
     $mois_selectionne = end($mois);
     return view('commande.facturation', compact('mois', 'mois_selectionne'));
 }